1. Field of the Invention
The present invention relates to a signal processing device, an imaging apparatus, a parameter generating method, a signal processing method, and a program, and in particular, relates to a technique for adjustment between a plurality of filter processes.
2. Description of the Related Art
As signal processing for changing and improving the quality of an image, filter processing, such as sharpening processing (outline enhancement processing, edge enhancement processing, or sharpness enhancement processing), point image restoration processing, and low pass processing, is generally known. Such filter processing is processing for emphasizing or suppressing the signal strength at a specific frequency by applying a filter to the signal, and the signal strength is adjusted according to the frequency characteristics of a filter to be used.
Accordingly, since an image signal having desired characteristics can be obtained by appropriately combining filter processes, these filter processes are used in order to achieve various objects.
For example, JP2011-123589A discloses image processing using an image restoration filter for reducing a phase degradation component and an edge enhancement filter for reducing an amplitude degradation component. JP2006-333061A discloses performing “image stabilization for performing edge enhancement processing after performing image restoration processing using an image restoration filter” and “image stabilization for simply performing edge enhancement processing”. JP2009-27750A discloses determining the degree of enhancement of outline components of a video signal according to conditions, such as a diaphragm at the time of imaging. JP2006-129236A discloses changing the strength of a restoration filter itself according to the edge strength by selecting filters having different restoration strengths according to the edge strength. JP2009-171320A discloses an imaging apparatus that performs appropriate noise removal corresponding to the focal length by adjusting the degree of noise reduction by a noise reduction (NR) processing unit and the degree of edge enhancement by an edge enhancement processing unit.